Noise reduction plate in gas fired combustion systems

ABSTRACT

A noise reduction plate for a thermal transfer device can include a body having plurality of apertures. The noise reduction plate is installed in the distribution channel of a premix blower and reduces ignition noise.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 16/449,203, filed 21 Jun. 2019, the entire contents of which is incorporated by reference as if fully set forth below.

TECHNICAL FIELD

Embodiments described herein relate generally to noise reduction assemblies in gas fired combustion systems, and more particularly to noise reduction plates for use in such a system, wherein the noise reduction plate reduces noise during ignition.

BACKGROUND

Boilers, water heaters, and other similar devices are used to heat various types of liquids. These devices often use a burner in connection with a combustion process. One of the limitations with existing burners is that, during ignition, the combustion process can generate noise such as a rumbling sound.

Referring to the attached figures, FIG. 1 is a schematic diagram showing the primary components of a typical boiler known in the prior art. Specifically, FIG. 1 illustrates boiler 100 with water inlet 114, water outlet 115, combustion chamber 108, heat exchanger 109, and flue gas outlet 116. Air is provided to a blower 105 and manifold 106 via an air input 102 and fuel is provided to the blower 105 and manifold 106 via a fuel input 104. The fuel and air mixture is received at the burner 110 within the combustion chamber 108 where they are ignited to produce a combustion product. The combustion product flows under the pressure of the blower 105 through the heat exchanger 109 to heat water within the boiler 100. After transferring heat to the water, the combustion products exit the boiler via the flue gas outlet 116. In the example illustrated in FIG. 1, the combustion chamber 108 has a cylindrical shape and is enclosed except for a combustion chamber inlet 107, in which the burner 110 is placed, and a combustion chamber outlet 111. The combustion chamber outlet 111 is in fluid communication with a heat exchanger inlet 112. A heat exchanger outlet 113 is in fluid communication with the flue gas outlet 116. In this example, the blower 105 outlet ends at a distribution channel 117, which then connects to the manifold 106.

In some combustion-based heat exchange systems, during ignition gas and air are premixed before reaching a burner. During ignition, gas and air flow through the heater and the burner is ignited, such that the gas starts to burn. In some cases, transient noise, for example rumbling, during ignition can occur due to sudden pressure changes within the system. The following disclosure describes example ignition noise reduction plates that can address one or more of the foregoing limitations.

SUMMARY

In general, in one aspect, the disclosure relates to a noise reduction plate assembly for a thermal transfer device, wherein the noise reduction plate assembly comprises a premix blower comprising an air intake and a fuel intake, a distribution channel connected to the premix blower, and a noise reduction plate positioned within the distribution channel, wherein the noise reduction plate comprises a plurality of apertures. In some embodiments, the plurality of apertures are the same shape and in other embodiments, the plurality of apertures have different shapes or a mixture of different shapes and similar shapes. For example, at least one of the plurality of apertures can be a different shape than another one of the plurality of apertures. In some embodiments, the plurality of apertures are spaced symmetrically in the noise reducing plate, and in other embodiments the plurality of apertures are spaced asymmetrically in the noise reducing plate. In some embodiments there are 2-500, 2-250, 250-500, 2-100, 100-200, 200-300, 300-400, or 400-500 apertures.

Another general embodiment of the disclosure is a boiler system, wherein the boiler system comprises a premix blower comprising an air intake and a fuel intake, a manifold, a distribution channel fluidly connecting an outlet of the premix blower to an input of the manifold, a burner fluidly connected to an outlet of the manifold, a combustion chamber fluidly connected to the burner, a water inlet, a heat exchanger comprising a plurality of heat exchanger tubes configured to receive heated gases from the combustion chamber and wherein the heat exchanger is fluidly connected to the water inlet such that water from the water inlet moves through the heat exchanger and outside of the heat exchanger tubes, a hot water outlet connected to the heat exchanger configured to receive heated water from the heat exchanger, an exhaust fluidly connected to the heat exchanger tubes; and a noise reduction plate comprising a plurality of apertures, wherein the noise reduction plate is positioned between an outlet of the premix blower and the inlet of the mixing chamber. In some embodiments, the noise reduction plate is located within the distribution channel. In embodiments, the plurality of apertures are the same shape and in some embodiments at least one of the plurality of apertures is a different shape than another one of the plurality of apertures. In specific embodiments, the plurality of apertures are spaced symmetrically in the noise reduction plate, and in other embodiments the plurality of apertures are spaced asymmetrically in the noise reduction plate.

Another general embodiment of the disclosure is a pre-mixed combustion system, wherein the pre-mixed combustion system comprises a premix blower comprising an air intake and a fuel intake, a mixing chamber, a distribution channel fluidly connecting an outlet of the premix blower to the mixing chamber, a burner fluidly connected to the mixing chamber; a heat exchanger comprising a plurality of heat exchanger tubes, an exhaust fluidly connected to the heat exchanger; and a noise reduction plate comprising a plurality of apertures, wherein the noise reduction plate is positioned between an outlet of the premix blower and the inlet of the mixing chamber. In some embodiments, the mixing chamber comprises a manifold. In embodiments, the noise reduction plate is located within the distribution channel. In some embodiments, at least one of the plurality of apertures is a different shape than another one of the plurality of apertures. In specific embodiments, the plurality of apertures are spaced symmetrically in the noise reduction plate, and in other embodiments, the plurality of apertures are spaced asymmetrically in the noise reduction plate. In some embodiments, the pre-mixed combustion system is a furnace or a boiler.

These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate only example embodiments of noise reduction plates and noise reduction plate assemblies and are therefore not to be considered limiting of its scope, as noise reduction plates and noise reduction plate assemblies may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

FIG. 1 is a schematic illustration of the primary components of a boiler as known in the prior art.

FIG. 2 is a schematic illustration of the primary components of a boiler in accordance with an example embodiment of this disclosure.

FIG. 3 is a schematic illustration of the primary components of a furnace in accordance with an example embodiment of this disclosure.

FIG. 4 shows a generic blower outlet pattern.

FIGS. 5a-d show example patterns in example noise reduction plates. FIG. 5a shows an example pattern comprising circles. FIG. 5b shows an example pattern using triangles. FIG. 5c shows an example pattern with squares. FIG. 5d shows an example pattern with ovals.

FIG. 6 is a photo of an example noise reduction plate.

FIG. 7 is a photo of a second example noise reduction plate.

FIG. 8 is a photo of a third example noise reduction plate.

FIG. 9 is a photo of a fourth example noise reduction plate.

FIG. 10 is a photo of a fifth example noise reduction plate.

FIG. 11 is a photo of a sixth example noise reduction plate.

FIG. 12 is a photo of a seventh example noise reduction plate.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The example embodiments discussed herein are directed to systems, methods, and devices for noise reduction plates and noise reduction plate assemblies. Example embodiments can be directed to any of a number of thermal transfer devices that include combustion systems, including but not limited to furnaces, boilers, condensing boilers, heat exchangers, and water heaters.

Example embodiments can be pre-fabricated or specifically generated (e.g., by shaping a malleable body) for a blower or tubing. Example embodiments can have standard or customized features (e.g., shape, size, features on the inner surface, pattern, configuration). Therefore, example embodiments described herein should not be considered limited to creation or assembly at any particular location and/or by any particular person.

The noise reduction plates and noise reduction plate assemblies (or components thereof) described herein can be made of one or more of a number of suitable materials and/or can be configured in any of a number of ways to allow the tubes in which the noise reduction plates and noise reduction plate assemblies are disposed) to meet certain standards and/or regulations while also maintaining reliability, regardless of the one or more conditions under which the noise reduction plates and noise reduction plate assemblies can be exposed. Examples of such materials can include, but are not limited to, aluminum, stainless steel, ceramic, fiberglass, glass, plastic, and rubber.

As discussed above, noise reduction plates and noise reduction plate assemblies (or vessels in which noise reduction plates and noise reduction plate assemblies are disposed) can be subject to complying with one or more of a number of standards, codes, regulations, and/or other requirements established and maintained by one or more entities. Examples of such entities can include, but are not limited to, the American Society of Mechanical Engineers (ASME), American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), Underwriters' Laboratories (UL), American National Standard Institute (ANSI), the National Electric Code (NEC), and the Institute of Electrical and Electronics Engineers (IEEE). An example noise reduction plate and/or noise reduction plate assembly allows a vessel (e.g., boiler, heat exchanger) to continue complying with such standards, codes, regulations, and/or other requirements. In other words, an example noise reduction plate or noise reduction plate assembly, when disposed within a vessel, does not compromise compliance of the vessel with any applicable codes and/or standards.

Any example noise reduction plates and noise reduction plate assemblies, or portions thereof, described herein can be made from a single piece (e.g., as from a mold, injection mold, die cast, 3-D printing process, extrusion process, stamping process, or other prototype methods). In addition, or in the alternative, an example noise reduction plate or noise reduction plate assembly (or portions thereof) can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to epoxy, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to fixedly, hingedly, removeably, slidably, and threadably.

Components and/or features described herein can include elements that are described as coupling, fastening, securing, abutting, or other similar terms. Such terms are merely meant to distinguish various elements and/or features within a component or device and are not meant to limit the capability or function of that particular element and/or feature. For example, a feature described as a “coupling feature” can couple, secure, fasten, abut, and/or perform other functions aside from merely coupling.

A portion of an example noise reduction plate or noise reduction plate assembly can be coupled to a vessel using one or more independent devices that interact with one or more coupling features disposed on a component of the noise reduction plate or noise reduction plate assembly. Examples of such devices can include, but are not limited to, a pin, a hinge, a fastening device (e.g., a bolt, a screw, a rivet), epoxy, glue, adhesive, tape, and a spring. One coupling feature described herein can be the same as, or different than, one or more other coupling features described herein. A complementary coupling feature as described herein can be a coupling feature that mechanically couples, directly or indirectly, with another coupling feature.

Any component described in one or more figures herein can apply to any other figures having the same label. In other words, the description for any component of a figure can be considered substantially the same as the corresponding component described with respect to another figure. Further, a statement that a particular embodiment (e.g., as shown in a figure herein) does not have a particular feature or component does not mean, unless expressly stated, that such embodiment is not capable of having such feature or component. For example, for purposes of present or future claims herein, a feature or component that is described as not being included in an example embodiment shown in one or more particular drawings is capable of being included in one or more claims that correspond to such one or more particular drawings herein. For any figure shown and described herein, one or more of the components may be omitted, added, repeated, and/or substituted. Accordingly, embodiments shown in a particular figure should not be considered limited to the specific arrangements of components shown in such figure.

Example embodiments of noise reduction plates and noise reduction plate assemblies will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of noise reduction plates and noise reduction plate assemblies are shown. Noise reduction plates and noise reduction plate assemblies may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of noise reduction plates and noise reduction plate assemblies to those of ordinary skill in the art. Like, but not necessarily the same, elements (also sometimes called components) in the various figures are denoted by like reference numerals for consistency.

Terms such as “first,” “second,” “top,” “bottom,” “left,” “right,” “end,” “back,” “front,” “side”, “length,” “width,” “inner,” “outer,” “lower”, and “upper” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit embodiments of noise reduction plates and noise reduction plate assemblies. In the following detailed description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

FIG. 2 illustrates the primary components of boiler 200 with water inlet 114, water outlet 115, combustion chamber 108, heat exchanger 109, and flue gas outlet 116 in accordance with example embodiments of the present disclosure. Air is provided to a blower 105 and manifold 106 via an air input 102 and fuel is provided to the blower 105 and manifold 106 via a fuel input 104. The fuel and air mixture is received at the burner 110 disposed at the combustion chamber inlet 107 where the mixture is ignited to produce a combustion product. The combustion product flows under the pressure of the blower 105 through the combustion chamber outlet 111, and the heat exchanger inlet 112 to heat water flowing around the heat exchanger 109 within the boiler 200. After transferring heat to the water, the combustion products exit the heat exchanger outlet 113 to the flue gas outlet 116. In the example illustrated in FIG. 2, a noise reduction plate 201 is placed within the distribution channel 117 between the blower 105 and the manifold 106. Example noise reduction plates will be described in greater detail in connection with FIGS. 5a-5d below.

FIG. 3 shows a premixed gas fired combustion furnace system 300 illustrating another example embodiment in which a noise reduction plate can be implemented. An air intake 302 and a fuel intake 304 enter a premix blower 306 and exit a blower outlet 307 into a distribution channel 308. A noise reducing plate 310 is located within the distribution channel 308. An air/fuel manifold or mixing chamber 312 is separated from a combustion chamber 314 by a burner 316. The air and gas mixture is ignited at the burner and heated combustion gases from the combustion move from the combustion chamber 314 and into a heat exchanger 318 which comprises a plurality of heat exchanger tubes 319. An air moving device 320 in a blower chamber 322 moves air over the heat exchanger tubes 319 heating the air without mixing the air outside of the heat exchanger tubes 319 with the hot combustion gases inside the heat exchanger tubes 319. The hot combustion gases leave the combustion furnace system 300 through an exhaust 324. FIG. 3 is an example of a premixed gas fired combustion system in which the noise reduction plate can be used. The noise reduction plate can be used in any configuration of a premix combustion system. For example, alternate embodiments of premix combustion systems in which the noise reduction plate can be used include systems with different placement of the blower, blower chamber, heat exchanger, burner, and combustion chambers, for example.

In certain example embodiments, the air intake is located at the fan inlet. In some example embodiments, the fuel intake is located at the fan inlet, and in other embodiments the fuel intake is located at the fan outlet. Pre-mix blowers can also comprise gas tight housings, anti-static backward curved impellers, speed control, and other modifications. In certain example embodiments, the pre-mix gas blower mixes the correct ratio of air to fuel. For example, the pre-mix blower can mix about 10 parts air to about one part fuel. In some embodiments, this ratio can vary due to elevation or type of fuel. The pre-mix gas blower can be controlled automatically or by a controller. The pre-mix blower functions to blow the air and fuel towards the burner, through the burner, and into the heat exchanger tubes.

The air moving device, separate from the premix blower, generally is used to move the fluid (e.g. ambient air) to be heated through the heat exchanger outside of the heat exchanger tubes. That is, the fluid (e.g. ambient air) to be heated passes over the outside of the heat exchanger tubes and is kept separate from the hot combustion gases within the heat exchanger tubes. As the ambient air passes over the outside of the heat exchanger tubes heat is transferred from the hot combustion gases within the heat exchanger tubes to the ambient air passing over the outside of the heat exchanger tubes. The air moving device can be a fan, a blower, and/or any other device that can force the heated combustion gases toward the heat exchanger. The air moving device can be controlled automatically or by a controller.

As illustrated in both the example boiler shown in FIG. 2 and the example furnace in FIG. 3, a noise reducing plate may be located at any position along the distribution channel 117/308. For example, the noise reducing plate can also be located at the outlet of the premix blower where the distribution channel begins or at the inlet of an air/fuel manifold or mixing chamber where the distribution channel ends. The noise reducing plate can also be located anywhere in between the outlet of the pre-mix blower and an inlet of the air/fuel manifold or a mixing chamber. If there is no distribution channel, the noise reducing plate can be located at the outlet of the blower. The distribution channel can be part of the blower or it can be a separate channel that connects the blower to the manifold or a mixing chamber of a combustion system.

As illustrated in the example boiler shown in FIG. 2 and the example furnace shown in FIG. 3, the distribution channel provides an optimal position for the noise reduction plate because the diameter of the distribution chamber is more narrow than that of the mixing chamber or manifold 106/312 and the premix blower 105/306. In other words, the distribution channel provides a controlled uniform flow of the air/fuel mixture through a more narrow area and along a length that facilitates further manipulation of the flow of the air/fuel mixture. Placing the noise reduction plate at an intermediate point along the distribution channel, as shown in the example embodiments of FIGS. 2 and 3, allows for further controlling and restricting the flow of the air/fuel mixture along the distribution channel. As described further below in connection with FIGS. 5a-5d , further restricting the flow of the air/fuel mixture is the goal of the noise reduction plate. Stated otherwise, the noise reducing plate 201/310 can be located in a fluid path downstream of the premix blower 105/306 to help reduce the noise generated by the premix blower 105/306. As will be appreciated by one of skill in the art, by locating the noise reducing plate 201/310 in a fluid path downstream of the premix blower 105/306, pressure waves generated by the blades of the premix blower 105/306 and propagated through the fluid (e.g., the air/fuel mixture) can be decoupled (i.e., broken into smaller segments and/or redirected to reduce the overall pressure of the pressure wave) by the noise reducing plate 201/306 to reduce the sound produced by the pressure waves. Although described herein as intended to decouple pressure waves produced by the blades of the premix blower 105/306, one of skill in the art will appreciate that the noise reducing plate 201/306 can be capable of decoupling pressure waves produced by other sources or components of the boiler 200 and/or combustion furnace system 300. For example, and not limitation, pressure waves can be produced by opening and closing of the air and fuel valves, flow of the air and fuel through piping, rotation of the bearings and/or shaft of the premix blower 105/306, or other components of the boiler 200 and/or combustion furnace system 300.

FIG. 4 illustrates an example blower outlet pattern 400 located at the outlet of the blower 105 or the blower 306. In the prior art, this blower outlet pattern is not modified.

FIGS. 5a-5d show various noise reduction plates 500 a-500 d in accordance with certain example embodiments. The noise reduction plates 500 a-500 d have a blower outlet pattern different from that shown in FIG. 4. The example embodiments each have a plurality of apertures 502 a-502 d which traverse through each noise reduction plate 500 a-500 d. As will be explained in greater detail in relation to each of FIGS. 5a -12 herein, the plurality of apertures 502 a-502 d in each example noise reduction plate 500 a-500 d can be strategically positioned and shaped to decouple the pressure waves generated by the premix blower 105/306 (or other sources of noise) and propagated through the air/fuel mixture. For example, as the pressure waves generated by the premix blower 105/306 pass through the noise reduction plate 500 a-500 d, the pressure waves can be decoupled to reduce the overall pressure exerted by the pressure wave and the resultant noise produced by the boiler 200 and/or combustion furnace system 300. As will become apparent, the shape and location of the apertures 502 a-502 d through the noise reduction plate 500 a-500 d can determine the extent to which the noise reduction plate 500 a-500 d is capable of decoupling the pressure wave.

FIG. 5a is an example noise reduction plate 500 a with 12 circular apertures 502 a placed in a symmetric pattern therethrough. The noise reduction plate 500 a can be used, for example, to reduce pressure waves generated by the premix blower 105/306. As will be appreciated by one of skill in the art, because the 12 circular apertures 502 a are placed in a symmetrical pattern through the noise reduction plate 500 a, the effectiveness of the noise reduction plate 500 a can be increased if the noise reduction plate 500 a is used in a system where the pressure waves passing through the noise reduction plate 500 are asymmetrically directed through the noise reduction plate 500 a. For example, in systems where the premix blower 105/306 is positioned or configured such that the pressure waves are directed toward the noise reduction plate 500 a asymmetrically, the pressure waves can be decoupled because portions of each individual pressure wave will contact the noise reduction plate 500 a at different points in time. As will be appreciated, as portions of each individual pressure wave contact the noise reduction plate 500 a at different points in time, some portions of the sound wave will be reflected away by the noise reduction plate 500 a while other portions of the pressure wave will be permitted to pass through the noise reduction plate 500 a—effectively decoupling the pressure wave.

FIG. 5b is an example noise reduction plate 500 b with 18 triangular apertures 502 b placed therethrough. Noise reduction plate 500 b can serve the same or similar function as noise reduction plate 500 a, however, as depicted, noise reduction plate 500 b can have the 18 triangular apertures 502 b placed asymmetrically therethrough. By placing the 18 triangular apertures 502 b asymmetrically in the noise reduction plate 500 b, the noise reduction plate 500 b can be configured to more effectively reduce pressure waves that are symmetrically directed toward the noise reduction plate 500 b than other noise reductions plates having a symmetrical aperture pattern (e.g., noise reduction plate 500 a). For example, by having the 18 triangular apertures 502 b placed asymmetrically through the noise reduction plate 500 b, a pressure wave that is symmetrically directed toward the noise reduction plate 500 b would have unequal portions of the pressure wave reflected from the noise reduction plate 500 b while other unequal portions are permitted to pass through the noise reduction plate 500 b because of the asymmetrical aperture pattern. Similarly, pressure waves that are asymmetrically directed toward the noise reduction plate 500 b would have unequal portions of the pressure wave reflected from the noise reduction plate 500 b while other unequal portions are permitted to pass through the noise reduction plate 500 b because of the asymmetrical aperture pattern. Furthermore, by having a triangular shaped apertures 502 b, the pressure waves can be further decoupled as the portions of the pressure wave that are permitted to pass through the noise reduction plate 500 b will be unevenly propagated through the triangular shaped apertures 502 b.

FIG. 5c is an example noise reduction plate 500 c with 21 square apertures 502 c placed asymmetrically therethrough. The noise reduction plate 500 c can perform the same or similar function as noise reduction plate 500 b but will have a different decoupling effect on the pressure waves because of the location and shape of the 21 square apertures 502 c. As with noise reduction plate 500 b, the noise reduction plate 500 c can be more effective at decoupling pressure waves that are asymmetrically directed toward the noise reduction plate 500 c than noise reduction plates having a symmetrical aperture pattern.

FIG. 5d is an example noise reduction plate 500 d with 8 different sized oval apertures 502 d placed asymmetrically therethrough. The oval apertures 502 d can be different sizes to help further decouple the pressure waves. For example, some of the oval apertures 502 d can be larger to permit a greater amount of the pressure wave to pass through the noise reduction plate 500 d while some of the oval apertures 502 d can be smaller to permit a lesser amount of the pressure wave to pass through the noise reduction plate 500 d. As will be appreciated by one of skill in the art, any of the apertures 502 a-502 c can similarly comprises varying sizes to further decouple the pressure waves and reduce the over all noise of the boiler 200 and/or combustion furnace system 300

The noise reduction plate 600 of FIG. 6 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 600 with apertures 602, a rumbling noise was heard during ignition. After installation of noise reduction plate 600, the noise during ignition was greatly reduced and ignition was smoother. As will be appreciated by one of skill in the art, by having apertures 602 of various sizes and placed in various locations on the noise reduction plate 600, the noise reduction plate 600 can be configured to decouple both symmetrical and asymmetrical pressure waves passed through the noise reduction plate 600 as described previously. Furthermore, by forming the noise reduction plate 600 with a round outer perimeter, the noise reduction plate 600 can be installed in a rounded distribution channel.

The noise reduction plate 700 of FIG. 7 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 700 with apertures 702, a rumbling noise was heard during ignition. After installation of noise reduction plate 700, the noise during ignition was greatly reduced and ignition was smoother. As will be appreciated by one of skill in the art, by having apertures 702 of various sizes and placed in various locations on the noise reduction plate 700, the noise reduction plate 700 can be configured to decouple both symmetrical and asymmetrical pressure waves passed through the noise reduction plate 700 as described previously. Furthermore, by forming the noise reduction plate 700 with a rectangular outer perimeter, the noise reduction plate 700 can be installed in a rectangular distribution channel.

The noise reduction plate 800 of FIG. 8 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 800 with apertures 802, a rumbling noise was heard during ignition. After installation of noise reduction plate 800, the noise during ignition was greatly reduced and ignition was smoother. Similar to noise reduction plate 600, by having apertures 802 of various sizes and placed in various locations on the noise reduction plate 800, the noise reduction plate 800 can be configured to decouple both symmetrical and asymmetrical pressure waves passed through the noise reduction plate 800 as described previously. Furthermore, by forming the noise reduction plate 800 with a round outer perimeter, the noise reduction plate 800 can be installed in a rounded distribution channel.

The noise reduction plate 900 of FIG. 9 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 900 with apertures 902, a rumbling noise was heard during ignition. After installation of noise reduction plate 900, the noise during ignition was greatly reduced and ignition was smoother. As will be appreciated by one of skill in the art, by having apertures 902 of various sizes, even if spaced symmetrically across the noise reduction plate 900 as depicted in FIG. 9, pressure waves can be decoupled more effectively by the noise reduction plate 900 than noise reduction plates having apertures of the same size spaced symmetrically.

The noise reduction plate 1000 of FIG. 10 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 1000 with apertures 1002, a rumbling noise was heard during ignition. After installation of noise reduction plate 1000, the noise during ignition was greatly reduced and ignition was smoother. The noise reduction plate 1000 can be similar to noise reduction plate 500 a described previously. For example, noise reduction plate 1000 can be more effective at reducing a pressure wave directed asymmetrically toward the noise reduction plate 1000 than a pressure wave directed symmetrically toward the noise reduction plate.

The noise reduction plate 1100 of FIG. 11 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 1100 with apertures 1102, a rumbling noise was heard during ignition. After installation of noise reduction plate 1100, the noise during ignition was greatly reduced and ignition was smoother. The noise reduction plate 1100 can be similar to noise reduction plates 500 a and 1000 described previously. For example, noise reduction plate 1100 can be more effective at reducing a pressure wave directed asymmetrically toward the noise reduction plate 1100 than a pressure wave directed symmetrically toward the noise reduction plate. Furthermore, by having a greater number of apertures than noise reduction plate 1000, noise reduction plate 1100 will decouple pressure waves differently than noise reduction plate 1000 by decoupling the pressure waves into smaller individual segments.

The noise reduction plate 1200 of FIG. 12 was installed in a pre-mixed combustion system and tested. Prior to installation of the noise reduction plate 1200 with apertures 1202, a rumbling noise was heard during ignition. After installation of noise reduction plate 1200, the noise during ignition was greatly reduced and ignition was smoother. The noise reduction plate 1200 can be similar to noise reduction plates 500 a, 1000, and 1100 described previously. For example, noise reduction plate 1200 can be more effective at reducing a pressure wave directed asymmetrically toward the noise reduction plate 1200 than a pressure wave directed symmetrically toward the noise reduction plate. Furthermore, by having apertures of a slightly greater size than noise reduction plate 1100, noise reduction plate 1200 will decouple pressure waves differently than noise reduction plate 1100 by decoupling the pressure waves into larger individual segments.

During ignition in prior art combustion systems, pressure waves can travel back toward the pre-mixed blower which can cause transient acoustics, such as a rumbling noise, due to sudden expansion and contraction of gases associated with combustion in the system. Not to be limited by theory, the noise reducing plate acts as a restricting element in the flow of the air and fuel mixture through the distribution channel 117, 308. Restricting the flow of the air and fuel mixture creates localized areas of high velocity flow through the apertures in the noise reducing plate. In embodiments, the plate plays a role in de-coupling the acoustic waves and results in changing the pressure waves, thus, silencing audible noise.

In other words, the total surface area of the apertures in the noise reduction plate can be less than the total surface area of a cross-section of the distribution channel, where the cross-section is parallel to the noise reduction plate. These localized areas of high velocity flow through the apertures of the noise reduction plate decouple the pressure on the outlet side of the noise reduction plate from the pressure on the inlet side of the noise reduction plate, thereby reducing ignition noise. That is, the high velocity jets created through movement of air through the apertures shown in the example noise reduction plates of FIGS. 5-12 are more resistant to back pressure waves than a fully open blower pattern as shown in FIG. 4. Therefore, the noise reduction plate reduces noise during ignition and smooths out ignition.

In certain example embodiments, the noise reduction plates can have a plurality of apertures that are spaced symmetrically or asymmetrically. Additionally, the apertures can be all the same shape or can be a mixture of different shapes. That is, the apertures can be square, triangular, rectangular, regular or irregular polygonal, circular, oval, an irregular shape or a mixture thereof. The apertures can be all one size or a mixture of different sizes. In some embodiments, there are 2-500 apertures in a noise reduction plate. In specific embodiments, there are 5-30, 5-100, 5-300, 300-500, 100200, 200-300, 300-400, or 400-500 apertures in a noise reduction plate. Additionally, the shape and/or size of one of the apertures of a noise reduction plate can be the same as, or different than, the shape and/or size of one or more of the other apertures of noise the reduction plate. As will be appreciated by one of skill in the art, depending on the particular configuration of the system, by combining a various shapes and configurations of apertures through the noise reduction plate, the noise reduction plate can be configured to more effectively decouple the pressure waves and reduce the overall sound produced by the system.

An example noise reduction plate can have a uniform or variable thickness. The noise reduction plate can have any thickness (e.g., one millimeter, one centimeter, one inch, 15 centimeters) needed for a particular application in which the example noise reduction plate can be used. The noise reduction plate can be made of and/or coated with a thermally conductive material. In addition, or in the alternative, the noise reduction plate can be made of and/or coated with a thermally non-conductive material.

In embodiments, the shape of the noise reduction plate generally matches that of the premix blower outlet or the distribution channel. For example, if the premix blower outlet is rectangular, the shape of the noise reduction plate can also be rectangular. In another example, if the distribution channel is circular, then the shape of the noise reduction plate can also be circular. In some embodiments, the noise reduction plate fits fully within the premix blower outlet or the distribution channel.

The various configurations, including aperture size, number of apertures, symmetric/asymmetric plate designs, and single/multiple relatively larger aperture variations, of example noise reduction plates described herein can help reduce the noise during ignition in a combustion system. Example embodiments can also be used in environments that require compliance with one or more standards and/or regulations. Example embodiments can be customizable with respect to any of a number of characteristics (e.g., shape, size, aperture configuration). Further, the shape, size, and dimensions of an example noise reduction plate can be specifically configured for a particular pre-mix blower, heat exchanger, or other vessel. Example embodiments can be mass produced or made as a custom order. The noise reduction plate can be installed prior to shipping or during installation of a particular combustion system. The noise reduction plate can also be installed as an aftermarket component in systems with noisy ignition. When installed, the noise reduction plate reduces noise during ignition and/or smooths out vibrations during ignition.

Accordingly, many modifications and other embodiments set forth herein will come to mind to one skilled in the art to which example noise reduction plates and noise reduction plate assemblies pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that example noise reduction plates and noise reduction plate assemblies are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this application. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

What is claimed is:
 1. A noise reduction plate assembly for a thermal transfer device, wherein the noise reduction plate assembly comprises: a premix blower comprising an air intake and a fuel intake; a distribution channel connected to the premix blower; and a noise reduction plate positioned within the distribution channel, wherein the noise reduction plate comprises a plurality of apertures spaced asymmetrically in the noise reduction plate.
 2. The noise reduction plate assembly of claim 1, wherein the plurality of apertures are the same shape.
 3. The noise reduction plate assembly of claim 1, wherein at least one of the plurality of apertures is a different shape than another one of the plurality of apertures.
 4. The noise reduction plate assembly of claim 1, wherein the plurality of apertures are each the same size.
 5. The noise reduction plate assembly of claim 1, wherein at least one of the plurality of apertures is a different size than another one of the plurality of apertures.
 6. The noise reduction plate assembly of claim 1, wherein there are 2-500 apertures.
 7. A boiler system, wherein the boiler system comprises: a premix blower comprising an air intake and a fuel intake; a manifold; a distribution channel fluidly connecting an outlet of the premix blower to an input of the manifold; a burner fluidly connected to an outlet of the manifold; a combustion chamber fluidly connected to the burner; a water inlet; a heat exchanger comprising a plurality of heat exchanger tubes configured to receive heated gases from the combustion chamber and wherein the heat exchanger is fluidly connected to the water inlet such that water from the water inlet moves through the heat exchanger and outside of the heat exchanger tubes; a hot water outlet connected to the heat exchanger configured to receive heated water from the heat exchanger; an exhaust fluidly connected to the heat exchanger tubes; and a noise reduction plate comprising a plurality of apertures spaced asymmetrically in the noise reduction plate, wherein the noise reduction plate is positioned between an outlet of the premix blower and the input of the manifold.
 8. The boiler system of claim 7, wherein the noise reduction plate is located within the distribution channel.
 9. The boiler system of claim 7, wherein the plurality of apertures are the same shape.
 10. The boiler system of claim 7, wherein at least one of the plurality of apertures is a different shape than another one of the plurality of apertures.
 11. The boiler system of claim 7, wherein the plurality of apertures are the same size.
 12. The boiler system of claim 7, wherein at least one of the plurality of apertures is a different size than another one of the plurality of apertures.
 13. A pre-mixed combustion system, wherein the pre-mixed combustion system comprises: a premix blower comprising an air intake and a fuel intake; a mixing chamber; a distribution channel fluidly connecting an outlet of the premix blower to the mixing chamber; a burner fluidly connected to the mixing chamber; a heat exchanger comprising a plurality of heat exchanger tubes; an exhaust fluidly connected to the heat exchanger; and a noise reduction plate comprising a plurality of apertures, wherein at least one of the plurality of apertures is a different size than another one of the plurality of apertures, and wherein the noise reduction plate is positioned between an outlet of the premix blower and an inlet of the mixing chamber.
 14. The pre-mixed combustion system of claim 13, wherein the mixing chamber comprises a manifold.
 15. The pre-mixed combustion system of claim 13, wherein the noise reduction plate is located within the distribution channel.
 16. The pre-mixed combustion system of claim 13, wherein at least one of the plurality of apertures is a different shape than another one of the plurality of apertures.
 17. The pre-mixed combustion system of claim 13, wherein the plurality of apertures are spaced symmetrically in the noise reduction plate.
 18. The pre-mixed combustion system of claim 13, wherein the plurality of apertures are spaced asymmetrically in the noise reduction plate.
 19. The pre-mixed combustion system of claim 13, wherein the pre-mixed combustion system is a furnace.
 20. The pre-mixed combustion system of claim 13, wherein the pre-mixed combustion system is a boiler. 